1. Field of the Invention
This disclosure relates to a rechargeable battery pack that connects a connection tab connecting unit cells of a rechargeable battery to a protection circuit module.
2. Description of the Related Art
With technological development of and a demand for a mobile apparatus, a demand for a rechargeable battery as an energy source has increased. The rechargeable battery may be used as a single cell type or a pack type electrically connecting a plurality of cells to each other depending on a kind of an apparatus using the rechargeable battery.
In general, a cylindrical rechargeable battery has a capacity larger than an angular rechargeable battery or a pouch-type rechargeable battery. The cylindrical rechargeable batteries are connected to each other in series, in parallel, or a combination thereof to form a rechargeable battery pack in a linear or plate structure.
A cell pack is formed by connecting the unit cells to each other by using a connection tab. The connection tab of the cell pack is also electrically connected to a protection circuit module (PCM) to form the rechargeable battery pack. The protection circuit module is included to protect the cell pack from overcharging, overdischarging, and short-circuit.
The protection circuit module may include a through-hole formed on a copper-clad pad. An end of the connection tab is inserted into the through-hole and the end of the connection tab and the pad are electrically connected to each other by soldering. In this arrangement, soldering locations of the end of the connection tab and the pad that are coupled to each other are arranged on the protection circuit module while being adjacent to a cylindrical unit cell.
During soldering, the cylindrical unit cell can interfere with the soldering process, resulting in the soldering iron tip not being able to accurately access the end of the connection tab and the pad. Consequently, a soldering failure may occur between the end of the connection tab and the pad of the protection circuit.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not constitute prior art as per 35 U.S.C. §102.